Inductance coil



Jan. 15, 1929. 1, 6 99, 117

S. L. NORVIEL INDUCTANCECOIL Filed Feb. 10. 1926 I/WT/VESS vi gzv K9. MM

UNITED STATES PATENT OFFICE.

SCOTT L. NORVIEL, LOS ANGELES, CALIFORNIA.

Application filed February 10, 1928.

INDUCTANCE COIL.

My invention relates to a construction of an inductance coil, and asupport therefor, principal ob ect the provision and has for its of animproved coil and supporting structure of a character which Wlll behighly eiiicient in use,

One of the principal ob ects of and inexpensive to manufacture.

my invention is the provision for an improved construction, of thecharacter described in which the inductance coils are so wound andmounted in relation to the supporting members as to reduce or tend toreduce to a minimum, the losses of electrical energy due to dielectricleakage by absorption, and inter-turn capacity. Also, I propose aconstruction of the character described, so designed as to dimin- 1Sl1losses of electrical energ and eliminate the undesirable effectsresultant irom such losses when these inductances are employed asinstruments in radio apparatus, as tuning inductances, radio frequencytransformers,

varlo-couplers and the like.

Other objects will appear hereafter.

The invention consists of the combinations and arrangements of partshereinafter described and claimed,and will be best understood byreference to the accompanying drawings which form a part of this and inwhich,

specification,

Fig. 1, is a side elevational View of a construction made in accordancewith my improvements; Fig. 3 is an end elevation thereof; and Fig. 2 isa cross sectional View, taken substantially on line 2-2 of Fig. 1.

Figure 3 represents the end view of the coil shown in Figure 1. Thisillustrates more fully the position and primary inductance 15,

construction of the Fig. 1. The slotted ring 1 1 is supported within thering 1 by the pressure of the flattened ends of the beams 16 and 17. Inthis slot the coil 15 is wound consisting of number of turns ofinsulated wire the inner lead being taken off at 1 5 and the outsidelead at 15".

Electrical connection is made to lugs 13-13-by bolts 1919.

It Will be readily understood, by those familiar with the art of radiotelegraphy and telephony, with their that losses of electrical energyattendant undesirable effects, are

in a majority of cases largely due to losses in the inductance coilscaused by winding the wire composing these inductances with sufiicientspacing between the consecutive turns and upon trio. Radio frequencycurrents, those of higher frequencies, tend and between an inefiicientdielecespecially to leap or Serial No. 87,229.

jump across from turn to turn of an inductance, unless these turns areseparated by a distance greater than that provided by the usual layer ofinsulation upon wire in common use, and in all dielectrics a certainamount of energy is lost, depending upon the amount of material used andthe manner and method of construction.

Heretot'ore, it has been customary to either wind such inductance coilsupon a solid cylindrical or prismatic core-form, or in a manner so thatthe coil will depend upon the support given by one turn to another forsuiticient rigidity to make its use practical, or to clamp or cement theturns in position one to another upon a supporting medium, so thatuniform spacing and rigidity might be maintained. These structures arecostly, incitcient, and unless wound upon substantial tubing, are toodelicate for practical use, and furthermore, the material usually usedand obtainable for these cylindrical ii'orms is a poorer dielectric forthese purposes than air.

y my invention I provide a device, manner and method of construction bywhich these coils may be wound upon a minimum of solid dielectricmaterial with turns separated by an air gap and constructed withrelative parts such that the whole structure is substantial and rigid.

Referring to the accompanying drawing, it will be seen that theconstruction includes two end-rings 1 and 2, connected at equispacedintervals by cross-beams 16 and 17 secured to the inner periphery ofsaid endrings by machine screws (3, 7, 18, 19 and 20. These rings aremade oi bakelite or other suitable insulating material, while the beamsare preferably of celluloid or other pliable elastic insulatingmaterial. I prefer to make these beams by bending or folding a thin fiatstrip of insulating material such as celluloid at an angle which mayeither approximate the right angle as illustrated in Figures 1 and 2 orbe an obtuse angle as illustrated in Figure 3. When constructed as inFigures 1 and 2, the beam is compound and composed of two strips 16 and17, the two sides 01 which bear upon each other, thus forming a T-beam.Upon and around the outer sides of these beams wire composing aninductance coil in helix form is wound, and the turns thereof securelycemented to each beam, or half thereof, with celluloid or other suitablecement.

In the optional form shown in Figure 3,

the wire 3 is wound inprismatic form and the cross-beams 16 consist ofstrips of thin celluloid or other suitable insulating material cementedon the inside of the coil at the angles of the prism faces, the centerof the strip conforming to the inside of the edge of the prismatic formand the sides of the fold thus formed conforming to the sides of theprism.

From the foregoing" description and drawin it will be seen that ineither form the structure of the device is made very firm and solid byreason of the angular bending of the st ips 16, 17, and 16", and thecementin of the turns of wire to them, and that therel 1 have provided avery simple inexpensive form of construction which will permit theconsecutive turns to be wound with an air space between them, and yetremain struce turally strong. and ru 'ged, and in which air is employedas a dielectric between the turns and for the most part the winding, andin whicl r solid dielectric supports for the coil are greatly reduced.Thus there is a lessening of losses of electrical energy, and consequently more efficient piece of apparatus is made, which makes possiblea substantial. improvement in the operaton of a radio set into which itmay be incorporated, evidenced both by th distance getting powers andselectivity of the set, and which at the same time is economical andinex Jensive to manufacture. By combining? the above descri ed structureas a secondary with the slot-wound primary 15, above descril-ied, theentire device becomes an exceedingly efficient transformer for radiofrequency currents due to the fact that there: is a maximum of magneticcoupling between the primary and secondary windings of the inductance,and a minimum of capacitative, (out of phase) coupling. The advantagesof this are obvious to those fa-n'iiliar with the art.

While I have described and illustrated the preferred form ofconstruction for carrying my invention into eiiect, it is obvious tothose skilled in the art that this is capable of. variation ormodification without departing from the fundamental idea or spiritthereof, and I desire, therefore, to be limited only by the followingclaims 1. In combination, in a device disclcsed, a helix of conductivematerial, a pair of end rings of dielectric material, a pluraly ofrelatively thin strips of flexible di i'c material supp-or said "ielixand ex ng' longitiidinaliy thereto, alongitudinal right angle told alongsaid strips, said i, 135 being placed in pairs with their supportingsides extending in opposite directi-ons along he inner periphery of saidhelix While their axially ez-iten'din Sit abut together, means for cenien-tit iousl y at aching the turns of the hel' 1 to the supporting sideof s id rip, means for supporting the entire device and attachinsi to abase board.

In a dei of the'liind disclosecha: helix of conductive material, a pairof end rings of dielectric i-i'iaterial approximately the size of saidhelix, a plurality of relatively thin strips of'celluloid supportingsaid helix and extending; longitudinally thereto, longitudinal rightangle fold along s "d strips, means for atta'cl of the kind lidlg theends ofsaid strips to said end rings'so that one flat side rests againstthe inner periphery of the helix while the other extends inwardlytoward: the axis thereof, said strips being placed in pairs their sidessupporting the helix extending in opposite directions along the innerperiplr= cry of said helix, while their axially extending sides abuttogether, means for cementitiously attaching the turns of the helix tothe supporting side of s' strip",- means for supporting the entiredevice and attaching to a base board,

In testimony whereof,- l have signed my name to these specifications;

